[3dem] Arginine and virus clump

[Juan Chang]

In my experience, 1M arginine will result in cryo images with very noisy
background, as if you had a carbon film substrate. My guess is that
under 500mM is ok. However, large viruses are usually very visible and
the extra noise may not matter to you.





On May 21, 2008, at 8:45 PM, Eduardo Sanz-Garcia wrote:

> I was wondering if that reagent would affect negatively our cryo (like 
> for example glucose).
>

Dear Eduardo,
What effect the arginine will have on cryo specimens depends on its
concentration.  Glucose used as a cryoprotectant is in the tens of
percent concentration range, and carbohydrate-containing granules, which
bubble before the rest of a cell, are even more concentrated.  If you
use ~50 mM arginine, you will be far below these concentrations, so
there should not be too significant an effect.  I have not tested this,
so I'm just guessing.

Yours,

Bill Tivol, PhD

EM Scientist

Electron Cryo-Microscopy Facility

Broad Center, Mail Code 114-96

California Institute of Technology

Pasadena CA 91125

(626) 395-8833

tivol at caltech.edu <mailto:tivol at caltech.edu>